Impulse sender



1941. H. DOHLE 2,251,666

IMPULSE SENDER Filed May 14, 1937 INVENTOR HINRICH DOHLE NEY ATTORPatented Aug. 5, 1941 IMPULSE SENDER Hinrich Diihle, Berlin-Haselhorst,Germany, assignor to Telephon-Apparat Fabrik E. Zwietnsch and Company,Berlin, Germany Application May 14, 1937, Serial No. 142,573 In GermanyJune 19, 1936 11 Claims.

The invention concerns an impulse sender having a series of keys commonto all the selecting stages for controlling the setting of switches intelephone systems. In the impulse senders known hitherto relay chains orstepping switches were associated with the individual selecting stagesand were set in correspondence with the selected digits and according totheir setting automatically transmitted selecting impulses.

The invention aims at reducing the switching means required forregistering the selecting impulses and for their subsequenttransmission. This advantage is realized in that instead of relay chainsor stepping switches condensers are used as registering means. Accordingto the invention a condenser is provided for each selecting stage and ischarged in accordance with the digit selected and by its dischargedetermines the number of impulses to be transmitted. The individualcondensers are connected in succession to a key set after each selectingoperation by a stepping switch. The keys are connected with a source ofcurrent over resistances of various magnitudes so that in accordancewith the digit which is keyed the condenser connected up over thestepping switch is charged to an extent dependent upon the resistanceconnected in the charging circuit, the length of charging beingcorrespondingly limited by a timing device.

An embodiment of the invention is represented in the drawing. Theimpulse sender possesses l setting keys T! to Til. When one of the keysTI to T0 is depressed the contact TT is closed at the same time. Eachkey is connected to a resistance Wil to Wi The key TI is. connected to aresistance whose other end is disconnected.

A six-digit selection is assumed in the embodiment. Accordingly onecondenser CI to C6 is provided for each selecting stage.

A rotary switch D, having a magnet DM and four sets of wipers DI, DII,DIII and DIV, is employed first to connect the condensers in successionto their charging circuits and, after they have been charged, to connectthem one after another to a common discharge circuit. This rotary switchmay be of the general type disclosed in Patent No. 1,675,311, grantedJune 26, 1928, to Hans Sengebusch, in which the wipers advance one stepupon each deenergization of the rotary magnet. In the presentarrangement, a resistance and a condenser are connected in series acrossthe winding of the rotary magnet; the condenser is charged when theenergizating circuit of the magnet is closed, and, upon the opening ofenergizing circuit, discharges through the magnet to maintain sameenergized for a short interval. The embodiment also includes eightrelays: A, B, H, V, W, X, Y and Z. Of these, relays V and W are of theslow acting type, and the rest, except relay B which has also been madeslow acting by a resistance shunt across its winding, are of the quickacting type. Each relay operates certain contacts lettered in thedrawing to correspond to that relay (for example, relay A has contactsla, 2a, 3a, 4a and 5a.).

The mode of operation of the circuit is as follows: Assuming that thefirst digit of the call number is 3, key T3 is depressed. Contacts T3and TT are closed, so that relay X draws up.

Earth-econtacts TT-,and 2z-relay X and battery. Relay X upon operatingcompletes the following circuit for charging condenser Cl:

Battery-contact T3--resistance Wz'3contacts 3rand 2y-wiper III ofswitch-Dcondenser C|contact 2:r-and earth.

At the same time it completes the above charging circuit, relay X alsocloses a circuit at contact Inc for relay Y, and as soon as relay Y hasoperated its armature the charging circuit for condenser CI is broken bycontact 2y. While relay Y is of the quick acting type as alreadymentioned, it will be appreciated that a short interval nevertheless isrequired for sufficient flux to build up in its winding to attract itsarmature, this interval being the same every time the relay isenergized. Hence, the charging circuit for relay Cl is closed for apredetermined short interval dependent upon the operating time of relayY. Relay Z is operated over contact ly and over contact is brings uprelay W. The operation of relay W is for the moment without effect. Bythe operation of relay Z, however, relay X is disconnected at contact2.2. After relay X has released the rotary magnet DM which operateswipers DI,-DIV is energized in the following circuit:

Earth, contacts inc and 32, magnet DM and battery. After relay X hasreleased relay Y also releases assoon as the key T3 has restored tonormal and contact TT is opened. After relay Y has released relay Z alsodeenergizes. On account of the opening of contact 3.2 the rotary magnetDM releases with the effect that the wipers DI-DIV are advanced by onestep. When now one of the keys TI ,to Ti) is depressed for the secondtime the condenser C2 is charged during the operating period of relay Yto an extent dependent upon the one of the resistances Wil to Will whichhas been connected up. It

may be assumed that Wii is an infinite resistance, and the remainingresistances are arranged on a scale of descending values, so that thecharge on any condenser will depend upon the key depressed. As the keysTI to TE! are depressed, therefore, the condensers Ci to C6 are chargedin succession. On the termination of the selection .the wipers DI--DIVstand on contact I. The transmission of the selected impulses independence upon the state of charging of the condensers Cl to C6 nowcommences. Relay A draws up over earth, wiper DI on steps fil2, contacts211) and lb, relay A, battery and earth, and disconnects the leadpassing to the selectors at the contact ta. Relay H operates overwinding HI over contact 3a in the following circuit:

Earth, winding I of relay H, contacts lh, 3a, and 412, battery andearth. Over contact la moreover, the slow-to-release relay V is causedto energize. Contact 41) opens the operating circuit of relay H, butbefore contact to opens contact 3v on closing completes a lockingcircuit for relay H which now holds up over windings I and II of relayH, resistance Wi, wiper DII on contact I, condenser C'l, contact 2x andbattery. The period during which relay H locks up is determined by thestate of charge of the condenser Cl. During this period when relay H isoperated relays A and B operate together as an automatic interrupter sothat a number of selecting impulses are transmitted by contact 4acorresponding to the state of charge of condenser Ci. Contact 2aoperates relay B which at contact i b deenergizes relay A. Relay A,however, can draw up again since contact 2h is closed throughout theperiod during which relay H is operated. As soon as the discharge ofcondenser Cl is completed relay H releases and relay A can no longerdraw up over contact 211. During the transmission of selecting impulsesby relay A relay V remains operated. Relay W was also operated overcontact I v. After relay V has released the rotary magnet DM operates inthe following circuit: Battery, magnet DM, contacts Iw and 211, wiper DIon contact I, earth. Contact Iv disconnects current from relay W so thatthe operating circuit for magnet DM is broken at contact lw and thewipers DI to DIV are advanced one step after magnet DM has released. Thesecond series of selecting impulses is now transmitted and is dependentupon the state of charge of the condenser C2. The switching operationsare repeated until the setting switch has again reached position I. Inorder to be able to tell at any time whether selecting impulses havebeen registered in the impulse sender a lamp BL is provided which lightsup as long as wiper DIV rests on contacts 2-42. In order to be able torestore the impulse sender to the normal position at any time areleasing key AT is provided. Assuming that the setting switch of theimpulse sender has already reached contact 3, then in order to renderthe three selecting digits already registered inoperative, the key AT isdepressed. This has the effect that relay X operates over earth, WiperDIV, contact IAT, contact 22, relay X and battery, whereby the switchingoperations are initiated which serve to advance the rotary magnet DM.Relay Y operates over contact I50 and at contact ly brings up relay Z.Relay X is released at contact 22. After the release of relay X therotary magnet DM receives current over contacts la: and 32. Relays Y andZ are deenergized so that relay X draws up again. Relays X, Y and Zoperate together in the manner of an automatic interrupter until wiperDIV has reached its original position. No discharge of the condenserstakes place during the setting of wipers DI to DIV since none of thekeys TI to T0 is depressed. The condensers Cl, 02 and C3 which in theexample assumed are already charged are discharged without efiect whenwiper D2 passes over the contacts 1, B, and 9, since relay V isenergized over key SAT. Relay H is not caused to operate by thedischarge current passing over contact 312.

What is claimed is:

1. In an impulse sending device, means for generating impulses of apredetermined character at a predetermined rate of speed, a condenser,means for charging said condenser to a certain voltage, means fordischarging said condenser through a resistance, and means forcontrolling first said means to generate impulses for an intervaldependent upon the period of time required to discharge said condenserthrough said resistance.

2. In an impulse sending device, a condenser, means for charging saidcondenser to a variable potential, a relay, means for operating saidrelay, means for discharging said condenser through said relay tomaintain said relay energized for the duration of said discharge, andmeans controlled by said relay for continuously generating impulses ofpredetermined character at a predetermined rate of speed for an intervalof time dependent upon the interval that said relay is maintainedenergized by said condenser.

3. In an impulse sending device, a plurality of condensers, means forcharging said condensers successively to any of a plurality of voltages,a relay, means for operating said relay once for each condenser in turnand for then discharging that condenser through said relay to control,in correspondence with the voltage to which that condenser Was charged,the length of time which said relay shall remain operated, meansoperated at a certain speed for generating a train of impulses duringeach operation of said relay, said relay eiiective to control, inacordance with the length of time it remains operated, the number ofimpulses in said train, and means for causing successive trains ofimpulses to be separated by a predetermined interval of time.

4. In an impulse sender for registering a plurality of digits asquantities of charge on a corresponding plurality of condensers andsubsequently re-transmitting each of the digits as one or more impulses;means for selectively charging said condensers to any of a plurality ofvoltages, each voltage corresponding to a digit to be registered, saidmeans comprising a source of electrical energy, a plurality of differentresistances and means for selectively connecting any one of saidresistances in series with said source and condenser for a predeterminedconstant time interval.

5. In a register, a condenser, means for charging the condenser to anyof a plurality of voltages, each voltage corresponding to a digit to beregistered, said means comprising a source of electrical energy, aplurality of different resistances, and means for selectively connectingany one of said resistances in series with said source and condenser fora predetermined constant time interval.

6. In a register, a condenser, means for charging the condenser to anyof a plurality of Voltages, each voltage corresponding to a digit to beregistered, said means comprising a source of electrical ener y, aplurality of different resistances, means operated to prepare a circuitfor charging said condenser through any one of said resistances, andtiming means operated responsive to said operation of said last means tocomplete said charging circuit for a predetermined constant timeinterval.

7. In a system for registering any digit as a quantity of charge on acondenser, the method of charging the condenser to any of a plurality ofdifferent voltages, each voltage corresponding to a digit, whichcomprises charging said condenser for a predetermined constant timeinterval at a rate of charge commensurate with the value of the digit tobe registered.

8. In an impulse sender, a condenser, means for charging said condenserto any one of a plurality of different potentials, means for thereafterdischarging said condenser continuously at a controlled rate, and meansfor generating impulses at a predetermined rate for an interval of timedependent upon the time required for said condenser to discharge.

9. In an impulse sender, a condenser, a discharge circuit for saidcondenser, means for charging said condenser to a certain value, meansfor subsequently connecting said condenser to said discharge circuit andmaintaining same connected thereto until substantially discharged, meansin said circuit effective during the discharging of said condenser tocontrol the rate of discharge of the condenser, and means fortransmitting impulses at a predetermined rate for an interval of timecorresponding to the time required for said condenser to discharge.

10. In an impulse sender, a plurality of condensers, means for chargingsaid condensers each to a certain potential, a discharge circuit, meansfor connecting said condensers successively to said circuit andmaintaining each connected thereto until substantially discharged, meansin said circuit for controlling the rate of discharge of each condenserwhen connected to said circuit, and means controlled by each condenserin turn to transmit impulses at a predetermined rate for an interval oftime depending upon the time required for that condenser to discharge.

11. In an impulse sender, a plurality of energy storage devices, meansfor storing in each of said devices a variable quantity of energy, meansfor subsequently releasing the stored energy from each devicecontinuously at a controlled rate until substantially all of said storedenergy has been released from that device, and an impulse generatorcontrolled by each device in turn to transmit impulses at apredetermined rate for a period of time corresponding to the timerequired for the release of the stored energy from that device.

HINRICH

